Wagga and District Family History Society volunteers have been left deeply upset after their Ashmont centre was broken into and two laptops were stolen.
Society vice president Rob Walker said the organisation was mainly affected by a "sense of invasion" after a person or persons broke an office window to gain entry on Monday night.
"It's very intrusive. We are only a voluntary organisation and we depend on our computers to index books in the library and a whole range of things in admin generally," he said.
"The laptops were used to help people with their inquiries online."
Mr Walker said it appeared that the intruders did not enter the building and instead reached through the window to obtain two laptops on a nearby shelf.
The building has motion sensors, including in the office where the window was broken, and an alarm system but it was not tripped during the break-in.
The society has been at its Tarakan Avenue premises since early 2008 and has previously had a window broken on another occasion and had a lawnmower stolen from its shed.
Mr Walker said the society would have to seek donations or hand-me-downs to replace the stolen laptops.
"There was data on the laptops but it would have been backed up," Mr Walker said.
The society has about 30 volunteers and 150 members who help people track down their family history in Wagga and is regularly contacted by people from across Australia and overseas.
"We had two people in yesterday who were researching a woman who had a shop in Wagga and they thought she had died in Wagga.
"We were able to find that she had actually died in Frenchs Forest and was buried there."
The society's building is owned by Wagga City Council, which has repaired the window.